Guard bolt construction for door locks



June 9, 1959 a. w. WARDWELL, JR ,0

GUARD BOLT CONSTRUCTION FOR DOOR LOCKS Original Filed June 28, 1954 2 Sheets- Sheet 1 INVENTOR =i= Wh n W ATTORNEYS Patented June 9; '1959 ori inal application June 2's, 1954, Serial N6. 439,528,

now Patent No. 2,800,347, dated July 23, 1957. Dividedand this application January 30, 1957, Serial swims. c1. 292; l69) The invention described in this application, which relates to a door lock and is a division of my application for Door Lock, Serial No. 439,528, filed June-28, 1954, now Patent No. 2,800,347, issued July 23, 1957, is particularly concerned with a guard bolt mechanism for preventing the forcing of the latch bolt by a tool inserted between the door strike and the door. v

As illustrated, the structure is applied to a latch bolt -mechanism comprising a casing adapted to be inserted in an opening bored into the edge'of the door and knob assembly adapted to be applied at each face of the door provided with knob shanks or spindles for actuating the latch bolt. Means are also provided for dogging the latch bolt against operation from the outside of the door as described in my previous application above referred to. In connection with such a structure, it is desirable when Unite S r Pm? Qfii the latch bolt is dogged against operation from the 'outside of the 'door to provide means for preventing the forcing of the latch bolt into retracted position by a tool inserted between the door and door strike. In the present application means are provided to effect this result in a relatively simple and economical manner and by means 'of mechanism which 'occupies a minimum amount of space within the lock case so that the opening in the door in which the case is received may be of relatively small size.

One object of this invention is toprovide new and improved guard bolt mechanism'for the door lock.

- A further object of the invention is to provide means for preventing the forcing of the latch bolt of a door lock by an'instrum'ent' inserted between the door and'door strike, which mechanismwill be of relatively simple construction, economical to manufacture, and will occupy a ,minimum of "space within the lockcase.

A further object of the invention is to provide guard mechanism for the latch bolt of a door which is controlled by a guard bolt mounted adjacent the latch bolt, and which guard bolt is adapted to cooperate with the door strike to control the position of the guarding or dog- 'ging member. I I

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and'claimed.

In the accompanying drawings: I I

Fig.- 1 is a frontelevational view of a door lock em bodying my invention;

Fig. 2 is a horizontal sectional view on line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view on line 33 of Fig. 2;

Fig. 4 is a partial sectional view similar to Fig. 2, showing the guard bolt in a retracted position;

Fig. 5 is a view similar to Fig. 2, showing both latch bolt and guard bolt in retracted position; and

Fig. 6 is a perspective view of the guarding lever.

To illustrate a preferred embodiment of my invention there is shown in Fig. 1 a portion of a door at 10 in 'whichis mounted a door lock mechanism comprising a casing ll'having a face plate 12 through which projects a latch bolt '13 reciprocably mounted in the I The latch bolt is' provided with a'stem 14, which stem projects rearwardly into the case and-is provided upon its rear end with lugs '15 "adapted to be engaged by th e rear face of the web or bight portion'1'6' of a'' U 'shaped retracting yoke having rearwardly extending legs 17. At

its rear "end each of the legs 17 of the "retracting yoke is provided with a cross head 18 having projecting lugs 19 at-each side thereof, which lugs are adapted to be engaged by one or the other of the rollbacks 20, I These rollbacks are carried by hu bs 21 r'otatably mounted in'the rear portionjof the casing 11am adapted to be rotatedby spindles 22 connected. to the knobs 23 and 24. A dogging member 25 is rotatably and slidably mounted in the casing 11 which is adapted to engage one or the other of the rollbacks '20 so as to dog one ofthe'se rollbacks' which'is operated by the outside knob indicated at 23 in Fig. 1. As the above structure is more specifical ly shown and described in my parent application referred to above, further description is unnecessary here. I

A latch boltspring 27 bears against the lugs 15 to urge the latch bolt to a projected position. The rear end of this spring bears against a spring stop 28 held by a ret'aining'or abutment member 29 secured to the lock case and extending transversely of the same. A second spring is'cammed into the case by the'jclosing of the 'door,'only the tension of the spring 27, which is relatively .light, mustbe 'ove'rc'ome,'-b 'ut when the bolt is withdrawn by the retracting yoke, both springs must be compressed,

It will also be understood that whe'n'either of the knobs 23 and 24 is rotated, one of the rollbacks 20 willalso be rotated and, by engaging one of the lugs 19, will .effect the retraction of the retractingyoke and will retract the latch bolt into the casing, as shown, for example, in Fig.5.

The guard mechanism for the latch bolt comprises a guard bolt 32 slidably mounted in the case at the back of the latch bolt, as shown'in Figs. 1, 2, 4 and 5. Secured to this guardQbolt is ,a guide plate 33 .sli d ably mounted .upon the stem 14ofthe latch bolt and, when the. guard bolt is in the position shownin Fig. 2, this guide plate is received in arecess 34. at therear face of the latch bolt. A spring 35 surrounds the stem ofthe latch bolt between the guide bolt and the light member 16 of the retracting yoke and normally urges the guard bolt to its protracted position, shown, for example, in .2.v

A guard or dogging lever 36 shown more especially in Fig. 6 is disposed in the case adjacent the guard bolt 32 and extends rearwardly therefrom The rear end .of this member 36 isprovided with a hooked portion 37 which extends through an opening in the abutment or retaining member 29.so as to be pivotedthereto to swing inwardly and outwardly toward and away from the latch bolt, as shown in Figs. 2, 4 and 5.

At the forward end of the lever 36 is provided an inwardly extending nose 38 which is adapted in the position shown in Fig. 4 to lie behind a portion of the latch bolt and dog it against retraction. A spring 39 of generally U'shaped form is supported upon the retaining member 29 and the free ends of this spring extend forwardly through openings in this member to urge it inwardly toward its position shown in Fig. 4. The ends of the spring act against a pair of laterally extending arms 40 provided upon the lever 36, these arms, as shown more especially in Fig. 3, extending out laterally over the legs 17 of the retracting yoke. As shown more especially in Fig. 2, the guard lever 36 is, when the guard bolt 32 is in its protracted position, held outwardly out of position to engage the head 13of the latch bolt by engagement of the nose 38 with a lug 41 carried by the guide plate 33 38 of the lever 36 is held out of engagement with the latch bolt 13. v e

As shown in Fig. 2, when the door is open, both guard bolt and latch bolt stand in protracted position and the nose 38 of the guard lever 36 rests upon the lug 41 and is thus held out of the'path of the latch bolt. When the door is closed, the latch bolt is cammed inwardly by contact with the strike. As the latch bolt engages the guide plate 33 of the guard bolt, the latter is so carried inwardlywith the latch bolt as shown in Fig. 5.

When the door reaches its fully closed position, as shown in Fig. 4, the latch bolt springs outwardly into the opening'in the door, strike but the guard bolt 32 is held in retracted position by engagement with the strike. In this position of the parts, shown in Fig. 4, the nose 38 of the guard bolt is moved inwardly by the spring 39 so that it lies behind the latch bolt and prevents movement of the latter inwardly by a tool inserted between the door strike and'the door. It will be understood at this time the guide plate 33 is in its inward position due to the retraction of the guard bolt 32 so that the lug 41 is no longer'in engagement with the nose 38 of the guard lever. When it is desired to open the door and the retractor is drawn rearwardly by rotation of one or the other of the knobs, the arms on the lever 36 are engaged by the cam surfaces 42 on the legs of the retractor and the guard lever is cammed outwardly against the action of the spring 39 so that the nose 38 no longer stands behind the bolt 13. Upon continued withdrawal of the retracting yoke, the bolt is completely retractedinto' the case and the door ispermitted to open. Upon the opening of the door and release of the knob, both the guard bolt and the latch bolt are moved by their respective springs to their protracted positions shown in Fig. 2.

While I have shown and described one embodiment of by invention, it willbe understood'that it is not to be limited to all'of the details shown, but is capable of modificationand variation within the spirit of the invention and within the scope of the appended claims. What I claim isz' 1. In a door lock mechanism having a casing, a latch bolt reciprocably mounted therein, knob-operated means forfiactuating the bolt including a retracting yoke recip rocably mounted in the casing, guard-bolt mechanism comprising a retaining member fixed to the case rearwardly of the bolt, a guard lever pivoted adjacent its rear end to said member and extending forwardly therefrom, adjacent the wall of the casing, to a point adjacent the bolt and adapted-to swing inwardly, in a horizontal direction, at its forward end, said lever having a nose portion at its forward end to engage the bolt and dog it against retraction, a guard bolt reciprocably mounted in the case adjacent the latch bolt, a member carried by the guard bolt and engaging the nose portion of the guard lever when the guard bolt is projected to hold the guard lever in inoperative position, said member being moved out of engagement with the nose portion when the guard bolt is retracted, spring means urging the lever inwardly to dogging position, said guard lever having laterally projecting arms thereon, and said retracting yoke having rearwardly extending legs provided with cam portions engaging said arms to move the guard lever to inoperative position when the yoke is retracted.

2. In a door lock mechanism having a casing, a latch bolt reciprocably mounted therein, knob-operated means for actuating the bolt including a retracting yoke reciprocably mounted in the casing, guard-bolt mechanism comprising a retaining member fixed to the case rearwardly of the bolt, a guard lever pivoted adjacent its rear end to said member and extending forwardly therefrom to a point adjacent the bolt and adapted to swing inwardly, in a horzontal direction, at its forward end, said lever having a nose portion at its forward end to engage the bolt and dog it against retraction, a guard bolt reciprocably mounted in the case adjacent the latch bolt, a guide plate secured to the guard bolt and disposed rearwardly of, and embracing the stem of, the latch bolt to be moved rearwardly by the latter upon its retraction, spring means also embracing the latch bolt and acting against said guide plate to urge the guard bolt to a projected position, and means on said guide plate to engage the nose portion of the guard lever when the guard bolt is projected tohold the guard lever in inoperative position.

3. In a door lock mechanism having a casing, a latch bolt reciprocably mounted therein, knob-operated means for actuating the bolt including a retracting yoke reciprocably mounted in the casing, guard-bolt mechanism comprising a retaining member fixed to the case rearwardly of the bolt, a guard lever pivoted adjacent its rear end to said member and extending forwardly therefrom to a point adjacent the bolt and adapted to swing inwardly, in a horizontal direction, at its forward end, said lever having a nose portion at its forward end to engage the bolt and dog it against retraction, a guard bolt reciprocably mounted in the case adjacent the latch bolt, said latch bolt having a rearwardly projecting stern, a guide plate secured to the guard bolt and slidably embracing said stem rearwardly of the latch bolt to be moved rearwardly by the latter when it is retracted, spring means surrounding the latch bolt stem and urging said guide plate forwardly in the casing, and means on said guide plate to engage said lever and hold it in non-dogging position when the guard bolt is in its forward position.

I References Cited in the file of this patent v UNITED STATES PATENTS Russell Apr. 17, 1956 

